Answer:
[tex]\huge\boxed{\bf\:2r^{7}}[/tex]
Step-by-step explanation:
Let the variable be taken as 'r'.
Then, by raising it to the 7th power, we'll get the result as [tex]\downarrow[/tex]
[tex]\sf\:Raise \: r \: to \: the \: 7^{th} \: power = r \: with \: 7 \: as \: its \: exponent.\\\\\sf\:Then,\\\dashrightarrow \underline{\bf\:r \: ^{7}}[/tex]
Now, by doubling the result....
[tex]\sf\:To \: double \: the \: result = multiply \: the \: result \: by \: 2.\\\\\sf\:Then,\\\dashrightarrow \sf\:r \: ^{7} \\=\boxed{\bf\: 2r\:^{7}}[/tex]
[tex]\rule{150pt}{2pt}[/tex]
